By heating which of the following, would NO₂ be produced?

1. NaNO₃

2. AgNO₃

3. NH₄NO₃

4. NH₄NO₂

The formation of ${\mathrm{PH}}_4^{+}$ is difficult as compared to ${\mathrm{NH}}_4^{+}$ because

1. Lone pair of phosphorous is optically inert.

2. Lone pair of phosphorous resides in almost pure p - orbital.

3. Lone pair of phosphorous resides at sp³ orbital.

4. Lone pair of phosphorous resides in almost pure s - orbital.

Iodine on reaction with concentrated nitric acid forms:

1. HOI

2. HI

3. HIO₃

4. HIO₄

Which of the following is the correct statement?

1. F₂ has higher dissociation energy than Cl₂

2. F has higher electron affinity than Cl

3. HF is stronger acid than HCl

4. Boiling point increases down the group in halogens

Incorrectly matched characteristic is:

1. S₈: covalent lattice

2. P₄: tetrahedron

3. S₅^2-: zigzag

4. SiO₂: Covalent lattice

Among the following reactions,  N₂ is not generated by heating:

1. (NH₄)₂Cr₂O₇

2. NH₄Cl + NaNO₂

3. NH₄Cl + CaO

4. Ba(N₃)₂

 An oxyacid among the following that contains both P-H and P-P bonds simultaneously is:

1. H₄P₂O₅

2. H₄P₂O₇

3. H₄P₂O₆

4. None of the above

Oxidation of nitrogen among the following reactions is indicated by -
1. \(\mathrm{N}_2 \rightarrow 2 \mathrm{NH}_3 \)
2. \(\mathrm{N}_2 \mathrm{O}_4 \rightarrow 2 \mathrm{NO}_2 \)
3. \(\mathrm{NO}_3{ }^{-} \rightarrow \mathrm{N}_2 \mathrm{O}_5 \)
4. \(\mathrm{NO}_2^{-} \rightarrow \mathrm{NO}_3^{-}\)

B(OH)₃ + NaOH  $\to$ NaBO₂ + Na[B(OH)₄] +H₂O

How can this reaction is made to proceed in forward direction?

1. addition of cis 1,2 diol

2. addition of borax

3. addition of trans 1,2 diol

4. addition of Na₂HPO₄

Which of the following has been arranged in order of decreasing bond dissociation energy:

1. P-O>Cl-O>S-O

2. P-O>S-O>Cl-O

3. S-O>Cl-O>P-O

4. Cl-O>S-O>P-O